The list is led by Zach Tuiasosopo (6-2, 249), the brother of Oakland Raiders quarterback Marques Tuiasosopo, who was consistently ranked by draft experts among the best of the fullback class.
Also on the list is Shippensburg (Pa.) running back John Kuhn (6-0, 255).
The Steelers hoped to emphasize linebackers in their free-agent class, and they signed three: Ronald Stanley (6-0, 244) of Michigan State, Andre Frazier (6-5, 234) of Cincinnati and Arnold Harrison (6-3, 236) of Georgia.
The only other rookie free agent added to the defense was tackle Elliott Harris (6-3, 285).
To help the offense, the also Steelers signed wide receivers Tavaris Capers (5-8, 174) of Central Florida and Nate Washington (6-1, 185) of Tiffin; tackle Morgan Davis (6-6, 330) of Wisconsin; and guard Jake Verstraete (6-6, 313) of Northern Illinois.
New to the special teams are long snapper Greg Warren (6-3, 252) of North Carolina and kicker Shaun Suisham (6-0, 199) of Bowling Green.
The group will report to Steelers headquarters with the rest of the team May 6-8 for minicamp.